Method of mounting magnetic disk device, cabinet for magnetic disk device, and magnetic disk device

ABSTRACT

The invention relates to the construction of an in-vehicle magnetic disk drive and a case for holding the in-vehicle magnetic disk drive. The in-vehicle magnetic disk drive must meet a condition peculiar thereto requiring normal operations under severe temperature conditions. An environment of an excessively low temperature disturbs a normal information recording operation, while an environment of an excessively high temperature makes the retention of recorded information impossible. The case is provided with a cold insulator, a heat insulator, a heat insulating material and a temperature sensor and is set in a specific position. The operation of the magnetic disk drive at temperatures outside a predetermined temperature range is inhibited.

TECHNICAL FIELD

The present invention relates to an information recording/reproducingdevice and, more particularly, to the construction of a case for holdingan information recording/reproducing device in an environment wheretemperature condition is severe on a magnetic disk, such as anenvironment in a vehicle.

BACKGROUND ART

Generally, a magnetic disk drive is held in a case provided with acooling fan as mentioned in Japanese Patent Laid-open No. 4-49590.Usually, the case is placed in a completely air-conditioned room.

Recent vehicles are equipped with a navigation system and otherelectronic systems. Those in-vehicle systems exchange information withexternal systems through a satellite, and mails can be sent out andreceived at optional places by mobile telephones. Thus, the amount ofinformation with which in-vehicle systems need to deal has progressivelybeen increased. To meet such a trend, an informationrecording/reproducing device for recording and reproducing informationincluding still pictures, animations and music numbers, particularly, amagnetic disk drive is necessary. A magnetic disk drive enables, forexample, a navigation system to achieve quick response and informationupdate. A magnetic disk drive is capable of downloading (storing) alarge amount of information through a private telecommunication networkusing ground waves and satellites or the Internet

Usually, the operating environment of a magnetic disk drive was in aroom, and the magnetic disk drive was held in a case provided with acooling fan. It has been a technical subject relating with thetemperature of the environment in which the magnetic disk drive operatesto control the temperature of a heat source to limit the upper limit oftemperature in the magnetic disk drive to, for example, about 50° C.

The temperature of the interior of a vehicle exceeds, sometimes, severaltens degrees Celsius when the vehicle is parked under a burning sun insummer and drops, sometimes, below −20° C. when in the morning inwinter. A magnetic disk drive mounted on a vehicle is exposed to such asevere thermal environment. In a low-temperature environment, therotation of magnetic domains and the displacement of magnetic domainwalls in a magnetic disk are difficult and the magnetic disk drive isunable to write information to the magnetic disk. In a high-temperatureenvironment, the rotation of magnetic domains and the displacement ofmagnetic domain walls in a magnetic disk occur easily. Consequently,written information cannot be held in the magnetic disk; that is, themagnetic disk is unable to keep storing information. An in-vehiclemagnetic disk drive is required to operate normally under vibrations.

DISCLOSURE OF INVENTION

A magnetic disk drive according to the present invention is providedwith a mechanism or parts facilitating placing the magnetic disk drivein and removing the same from a case to enable mounting the magneticdisk drive on a vehicle only when necessary. The magnetic disk drive canpermanently fixedly be mounted on a vehicle.

The ambient temperature, i.e., the temperature of a space surroundingthe magnetic disk drive, is measured by a temperature sensor placed inthe case holding the magnetic disk drive, and the magnetic disk drivehas a function to withhold its operation unless the ambient temperatureis within a temperature range suitable for the operation of the magneticdisk drive. The function to withhold operation is a function to inhibitthe connection of the magnetic disk drive to a power supply, a functionto generate a warning sound, a function to display warning light, afunction to display a message to that effect, a function to generate awarning voice or such. Thus, the safe operation of the magnetic diskdrive can be ensured even if the magnetic disk drive is left in thevehicle or the user forget to remove the magnetic disk drive from thevehicle. The temperature sensor may be placed inside the magnetic diskdrive.

The magnetic disk drive is disposed near an air outlet, through whichhot or cold air is blown out, of an air conditioning system to make thetemperature of the magnetic disk drive reach the ambient temperaturequickly. A cold insulator or a heat insulator is disposed in thevicinity of the magnetic disk drive for cases where the magnetic diskdrive is left in the vehicle. More specifically, a cold insulator or aheat insulator is placed in the case holding the magnetic disk drive,and the case is covered with a heat insulating material.

A heat source may be disposed inside the magnetic disk drive or near themagnetic disk drive. The heat source is, for example, a plate-shapedheater, a heater formed by arranging a linear heating element on aplate-shaped member having a high heat conductivity, such as a ceramicplate or a metal plate, or a flexible heater formed by arranging aresistance wire on a flexible printed circuit sheet (FPC sheet)

The temperature of the space surrounding the magnetic disk drive dropsand rises in a certain temperature range. A rotating shaft included in aspindle motor for rotating the magnetic disk, a rotating shaft includedin a carriage for carrying a magnetic head, and a base fixedly holdingcomponent parts may be formed of ceramic materials to prevent themisalignment of the magnetic disk and the magnetic head due to thermalexpansion.

The magnetic disk drive is fixedly held in a vehicle such that themoving directions of the carriage of the magnetic disk drive coincidewith vertical directions, and the surfaces of the magnetic disk areparallel to a lateral direction, in which less shocks act, with respectto the moving direction of the vehicle to prevent the adverse effect ofvibrations and shocks characteristic of the vehicle and to preventcollision between the magnetic disk and the magnetic head. The phrase“the moving directions of the carriage of the magnetic disk drivecoincide with vertical directions” signifies that the moving directionsof the carriage are substantially parallel to directions in which shocksact.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a sectional view of a preferred embodiment of the presentinvention showing a magnetic disk drive 5 held in a case;

FIG. 2 is a sectional plan view of the embodiment shown in FIG. 1;

FIG. 3 is a sectional view of a magnetic disk drive;

FIG. 4 is a plan view of a magnetic disk drive, in which a cover 15 isremoved;

FIG. 5 is a schematic view of the driver's seat and the passenger seatof a vehicle taken obliquely from behind; and

FIG. 6 is a schematic perspective view of a host apparatus 31 providedwith a holding chamber 32 for accommodating the magnetic disk drivetherein, in which a direction in which the magnetic disk drive 5 isloaded into the host apparatus 31 is indicated by the arrow.

BEST MODE FOR CARRYING OUT THE INVENTION

A preferred embodiment of the present invention will be described withreference to FIGS. 1 to 5.

FIG. 5 is a schematic view of the driver's seat and the passenger seatof a vehicle taken obliquely from behind. A console A has a centralconsole box provided with a gearshift lever 51 and built-in devices 52including automotive audio devices. A steering wheel 53 is disposedbehind a right part of the console A, and an automotive air conditioner,not shown, is disposed in a space 54 in a left part of the console A.The built-in devices include a personal computer and portable electronicdevices.

An in-vehicle magnetic disk drive holding case is disposed in a space B.The in-vehicle magnetic disk drive holding case is a case for holding amagnetic disk drive. Warm air or cool air blown by the automotive airconditioner flows around the case.

Although the in-vehicle case is shown typically to facilitaterecognizing the position of the in-vehicle case, ignoring design in FIG.5, actually, the in-vehicle case is designed integrally with the consoleA so that part of the passage of air blown by the air conditionerpenetrates the in-vehicle case.

If the in-vehicle case does not need to be cooled, i.e., if the magneticdisk drive does not need to be cooled, the in-vehicle case may bedisposed inside the console A irrespective of the passage of air blownby the air conditioner. In such a case, the recording medium of themagnetic disk to be driven by the magnetic disk drive must be formed ofa material having high coercive force and resistant to the effect ofhigh temperatures that causes magnetic domain rotation and magneticdomain wall displacement.

FIG. 1 is a sectional side elevation of the magnetic disk drive 5 andthe in-vehicle case 1 holding the magnetic disk drive 5.

The in-vehicle case 1 holding the magnetic disk drive 5 has a case bodyformed of a plastic material, and a heat-insulating layer 2 of aluminumcoating the outer surface of the case body to avoid exposing the casebody to direct sunlight and to keep the internal temperature of thein-vehicle case constant. The aluminum heat-insulating layer 2 is bondedto the plastic case body. The plastic case body may be coated with sucha coating by any other suitable process, such as an electrodepositioncoating process or a plating process.

The positional relation between the air vent of the air conditioner andan opening formed in the in-vehicle case 1 is determined such that warmair or cool air blown out by the air conditioner is able to flowefficiently into the case 1. More specifically, a lid 4 may serve as aguide plate for guiding air blown by the air conditioner. Air is able toflow efficiently through the case 1 when the case 1 is provided withanother opening.

A cold/heat insulator 3 is placed in the case 1 to keep the magneticdisk drive 5 at temperatures near the internal temperature of thecompartment of the vehicle. When a cold/heat insulating gel is used asthe cold/heat insulator 3, the cold/heat insulator 3 is function as ashock-absorbing material for holding the magnetic disk drive 5. Thecold/heat insulator 3 is bonded adhesively to the in-vehicle case 1.Alternatively, the cold/heat insulator 3 may fixedly be held in the case1 by holding projections formed on the case 1. When a cold/heatinsulating gel is used as the cold/heat insulator 3, the cold/heatinsulator is held in close contact with the magnetic disk drive 5.

The magnetic disk drive 5 is held in the in-vehicle case 1 by themechanical retaining force of its own connector. The case 1 may beclosed by the lid 4 to hold the magnetic disk drive 5 with reliability.If the lid 4 is used as a guide plate for guiding air blown by the airconditioner, an opening, i.e., a vent, is formed in a wall, not facingthe console, of the case 1 so that the aesthetic appearance of theconsole may not be spoiled. If the lid 4 is not closed, the magneticdisk drive 5 is fixed firmly with a holding member or a lockingmechanism, not shown.

When the magnetic disk drive 5 is inserted in and fixedly held in thein-vehicle case 1, i.e., when the magnetic disk drive 5 is held by thein-vehicle case 1, the magnetic disk drive 5 is connected forinformation transmission to in-vehicle electronic devices and isconnected to a power supply. If the user does not mind connecting themagnetic disk drive 5 to the power supply, the magnetic disk drive 5 maybe connected to the power supply by an additional operation.

A temperature sensor 22 is placed inside the invehicle case 1. Thetemperature sensor 22 is connected electrically to an electronic deviceby a cable 26. The electronic device performs a predetermined process onthe basis of an electric signal provided by the temperature sensor 22and, if a temperature measured by the temperature sensor 22 is above theupper limit or below the lower limit of a temperature range determinedfor the normal operation of the magnetic disk drive 5, gives notice tothe effect that the magnetic disk drive 5 is unable to operate. Thenotice may be given through an electronic device placed on the console,may be displayed by sending a signal to an LED, a liquid crystal displayor other display devices, or may be given by an electronic audio deviceplaced on the console. Practical means for giving the notice is, forexample, automatic inhibition of connection of the magnetic disk drive 5to the power supply, generation of a warning sound, lighting of a redLED or generation of a voice message to the effect that the temperatureis not in the operating temperature range.

FIG. 2 is a sectional plan view of the in-vehicle case 1 and themagnetic disk drive 5 contained in the in-vehicle case 1. The in-vehiclecase 1, as explained with reference to FIG. 5, may individually bedisposed in the vehicle or may be used as a docking bay for a hostelectronic device, such as another personal computer, a video device ora DVD device. The cold/heat insulator 3 surrounds the magnetic diskdrive. The case 1 may be provided with a plate-shaped heater or the likeinstead of the aluminum heat-insulating layer 2.

A plate-shaped heater 2′ is placed between the in-vehicle case 1 and themagnetic disk drive 5 inserted in the in-vehicle case 1. Power issupplied from an external power supply to the plate-shaped heater 2′ toheat the magnetic disk drive 5 so that the temperature of the magneticdisk drive 5 may not drop below a predetermined temperature. When thecase 1 is designed so as to meet cold-weather specifications, power issupplied to the plate-shaped heater from the battery of the vehicle, apower supply installed in a parking place or some other external powersupplies.

The basic configuration of the magnetic disk drive 5 will be describedwith reference to FIG. 3. Disks 19 each formed by forming a magneticfilm on an aluminum or glass substrate are capable of magneticallyholding information. A spindle motor rotates the disks 19. The spindlemotor includes a hub 12 supporting the magnetic disks 19 in layers, adisk clamp 6 for fastening the disks 19 to the hub 12, and a motor shaft17 held on a base 18 and supporting the hub 12 for ration by bearings.

Each of magnetic heads 7 floats above a surface of the disk 19 with afixed very small clearance of several tens nanometers to writeinformation magnetically to and to read information magnetically fromthe disk 19. The magnetic head 7 is provided with an electromagneticcoil capable of electromagnetically providing electric signalsrespectively corresponding to magnetic fields created by magneticdomains in the disk 19. The magnetic head 7 is formed on a ferrite baseof a laminated structure of metal thin films.

A carriage 13 for correctly positioning the magnetic head 7 relative tothe surface of the disk 19 is formed of a metal containing aluminum ormagnesium as a principal component. The carriage 13 is driven forpositioning by a voice-coil motor 9 including a coil 10 formed bycoiling an insulated aluminum or copper wire, a permanent magnet, and ayoke holding the coil 10 and the permanent magnet to form a magneticcircuit. The carriage 13, similarly to the spindle motor, is supportedfor turning by bearings on a carriage shaft 8 set on the base 18.

Referring to FIG. 4, electric signals are transmitted for reading andwriting from the magnetic head 7 through the fine wire of theelectromagnetic coil of the magnetic head 7 extended through thecarriage 13 to a flexible printed circuit board (FPC board) 23. Theelectric signal is transmitted from an HDA through a read/write controlboard 14 for controlling the read and write signal of the magnetic head7 and through an enclosed connector 21 underlying the read/write controlboard 14 to an external device. The enclosed connector 21 has a bodyformed of aluminum, a stainless steel or iron and is fixedly bondedadhesively to the base 18.

The HDA, i.e., the hard disk assembly, is a component, surrounded by thebase 18 and a cover 15, of the magnetic disk drive.

A temperature sensor 22′ may be placed inside the HAD. Signals providedby the temperature sensor 22′ are transmitted through the connector 21to an external device. An electronic device, i.e., a host device, iscapable of controlling the interior temperature of the HDA and thetemperature of an atmosphere surrounding the disks 19 with higheraccuracy.

The enclosed connector 21, through which the HDA exchanges electricsignals with external devices, has a plurality of pins, and a pin holderformed by molding. The pins and the pin holder are perfectly enclosed. Acoil drive current for driving the coil 10 is transmitted through theFPC 23 to the enclosed connector 21. A motor FPC connected to thespindle motor transmits a spindle motor drive current to the enclosedconnector 21. All the signal lines connecting the HDA to the externaldevices do not need necessarily to be connected through the enclosedconnector 21 to the external devices. For example, driving power fordriving the spindle motor may be supplied through separate wiring intothe HDA.

The enclosed connector 21 is connected to a main board 11 (FIG. 3) forcontrolling external devices provided outside the HDA. The shafts of thespindle motor and the carriage 13, and the voice-coil motor 9 arefastened to the base 18 with screws. The cover 15 of aluminum, stainlesssteel or iron is fastened to the base 18, the spindle motor, the shaftof the carriage 13 and the voice-coil motor 9 with screws with apacking, not shown, held for sealing between the cover 15 and the base18. The main board 11 is fastened to the base 18 with screws 16.

Existence of any foreign matter that obstructs a magnetic path in thespace between the magnetic head 7 and the disk should be avoided toprocess signals accurately when the magnetic head 7 writes or readsinformation to or from the disk 19. Therefore, the space must always bekept clean. The HDA is provided with an internal filter, not shown, tocatch dust contained in circulating air currents produced in the HDA bythe rotating disks 19.

The magnetic disk drive is provided with the plurality of disks 19 tohave a necessary storage capacity, and the magnetic heads 7 are disposedopposite to the surfaces of the disks 19, respectively. A disk spacer 20is placed between the adjacent disks 19. and the magnetic heads 7 aredisposed at predetermined intervals by accurately finishing mountingsurfaces, on which the magnetic heads 7 are mounted, of the carriage 13.

It is possible that the magnetic heads 7 collide with the disks 19 whena shock is given to the magnetic disk drive 5. The magnetic disk drive 5held on the vehicle such that the moving directions, i.e., seekdirections, of the carriage 13 are vertical to reduce the effect, thatcause the magnetic heads 7 to collide with the disks 19, of shocksmostly acting in vertical directions and peculiar to the vehicle. Themagnetic disk drive 5 is disposed with a line perpendicular to thesurfaces of the disks 19 extended in the moving direction of thevehicle, in which less shocks act (excluding collision and specialconditions), or laterally with respect to the moving direction of thevehicle. A vibration isolating material may be disposed in the vicinityof the cold insulator 3 to enhance the vibration proof.

In the embodiment shown in FIG. 3, the heater 2′ is applied to the cover15. The heater 2′ may be applied to the main board 11. The base 18, thecover 15 and the main board 11 may be packed in an outer package. Theouter package may cover only a part of the magnetic disk drive. Theouter package is a decorative case of a predetermined designfacilitating carrying the magnetic disk drive 5. When necessary, theheater 2′ may be interposed between the outer package and the magneticdisk drive 5.

FIG. 6 shows a host device 31 provided with a chamber 32 for fitlyholding the magnetic disk drive 5 therein. In FIG. 6, the arrowindicates a direction in which the magnetic disk drive 5 is inserted inthe chamber 32. The plate-shaped heater 2′ is placed between the hostdevice 31 and the magnetic disk drive 5. A connector 33 connects themagnetic disk drive 5 electrically to external devices and has amechanical ability to hold the magnetic disk drive 5 in place. The hostdevice 31 manipulates information recorded in the magnetic disk drive 5for predetermined information processing and records the results ofinformation manipulation in the magnetic disk drive 5.

When the temperature of the magnetic disk drive 5 is not in thetemperature range for the normal operation of the magnetic disk drive 5,the magnetic disk drive 5 gives information to that effect to the hostdevice 3. The host device 31 measures the temperature and holds aninoperative mode for not processing information and provides a signal tothat effect. The signal representing the inoperative mode may be a voicesignal, an image signal to be displayed by a display or a warningexpressed by lighting an LED.

When the magnetic disk drive 5 can easily be put in and taken out of thecase, it is convenient for carrying and storing the magnetic disk drive5 to pack the magnetic disk drive 5 taken out of the in-vehicle case 1or the case of the host device 31, i.e., an electronic device, in anouter package capable of entirely covering the magnetic disk drive 5.The magnetic disk drive 5 is packed in a package formed by molding aplastic material or the like and capable of covering the cover 15 andthe base 18 of the magnetic disk drive 5 shown in FIG. 3.

The magnetic disk drive 5 packed in the outer package may be inserted inthe in-vehicle case 1. In addition, the magnetic disk drive 5 with theouter package may be taken out of the case if necessary and carriedaround to protect the magnetic disk drive 5 from a severe environment.

If the magnetic disk drive 5 is not removed from the case and isinstalled permanently in the vehicle, the plate-shaped heater isinterposed between the cover 15 or the base 18 (FIG. 3) and the outerpackage, which improves thermal efficiency and hence the magnetic diskdrive 5 can be kept at a proper temperature by less power.

The accuracy of monitoring the heating performance of the heater caneasily be improved and the internal temperature of the magnetic diskdrive 5 can easily be kept at a fixed level by placing a temperaturesensor inside the magnetic disk drive 5.

As apparent from the foregoing description, the present inventionprovides the magnetic disk drive and a case capable of holding themagnetic disk drive in the vehicle.

1. A magnetic disk drive holding method of mounting a magnetic diskdrive contained in a case and including rotating magnetic disks,magnetic heads for writing or reading information to or from themagnetic disks, and a carriage for moving the magnetic heads on themagnetic disks on a vehicle, said method comprising the steps of:holding the magnetic disk drive such that the moving directions of thecarriage of the magnetic disk drive coincide with a vertical directionrelative to the vehicle; holding the magnetic disks such that thesurfaces of the magnetic disks are parallel to a lateral directionrelative to the vehicle, forming an opening in the case; and disposingthe case near an air vent of an air conditioner included in the vehicle.2. The magnetic disk drive holding method according to claim 1, whereinthe case is provided with a cold insulator for keeping the magnetic diskdrive cool or a heat insulator for keeping the magnetic disk drive warm.3. The magnetic disk drive holding method according to claim 1, whereina heater is provided between the disk drive and the case.
 4. Themagnetic disk drive holding method according to claim 1, furthercomprising the steps of: providing a temperature sensor for measuringthe temperature inside the case, providing a cable for connecting thetemperature sensor electrically to an electronic device which performs apredetermined process on the basis of an electric signal provided by thetemperature sensor, sending a notice from said electronic device to saidmagnetic disk drive if a temperature measured by the temperature sensoris above the upper limit or below the lower limit of a temperature rangedetermined by the normal operation of the magnetic disk drive and,inhibiting connection to a power supply or issuing a warning on thebasis of the notice.
 5. The magnetic disk drive holding method accordingto claim 2, wherein the cold insulator or the heat insulator serves alsoas a shock absorber.